The human mitotic kinesin Eg5 represents a novel mitotic spindle target for cancer chemotherapy. We previously identified S-trityl-L-cysteine (STLC) and related analogues as selective potent inhibitors of Eg5. We herein report on the development of a series of 4,4,4-triphenylbutan-1-amine inhibitors derived from the STLC scaffold. This new generation systematically improves ...

Galectin-1 and galectin-3 have roles in cancer and inflammation. Galectin-1 has recently emerged as a significant protein produced by tumour cells to promote tumour development, angiogenesis and metastasis and consequently represents an important target to inhibit. The design of inhibitors targeting the carbohydrate recognition domain that is known to recognize ...

A variety of tumour necrosis factor α (TNF-α) derivatives have been bioengineered to improve antitumour activity and reduce toxicity. The expression of TNF-α in Escherichia coli usually yields a mixture of homotrimers and monomers; however, only the trimer shows antitumour activity. TNF-αD10, a bioengineered hTNF-α derivative, demonstrated 10-fold higher cytotoxicity ...

Clinical proteomic profiling by mass spectrometry (MS) aims at uncovering specific alterations within mass profiles of clinical specimens that are of diagnostic value for the detection and classification of various diseases including cancer. However, despite substantial progress in the field, the clinical proteomic profiling approaches have not matured into routine ...

Objectives  P-glycoprotein (Pgp) overexpression in tumour cells leads to multidrug resistance (MDR) and causes failure in cancer chemotherapy. We have previously identified (±)-praeruptorin A (PA) as a potential lead compound for Pgp modulators. In this study we investigated the MDR-reversing activities of PA derivatives. Methods  Series 7,8-pyranocoumarins with various C-3' ...

Indoleamine 2,3-dioxygenase-1 (IDO-1) is a heme containing enzyme that catalyses the initial step in the major pathway of l-tryptophan catabolism; the kynurenine pathway. A large body of evidence has been accumulating for its immunosuppressive and tumoural escape roles and its applicability as a therapeutic target. Of particular interest is the ...

Mammalian heparanase is an endo-β-glucuronidase associated with cell invasion in cancer metastasis, angiogenesis, and inflammation. Heparanase cleaves heparan sulphate proteoglycans in the extracellular matrix and basement membrane, releasing heparin/heparan sulphate oligosaccharides of appreciable size. This in turn causes the release of growth factors, which accelerate tumour growth and metastasis. Heparanase ...

Human neutrophil elastase (HNE) plays an important role in tumour invasion and inflammation. A series of N-benzoylindazoles was synthesized and evaluated for their ability to inhibit HNE. We found that this scaffold is appropriate for HNE inhibitors and that the benzoyl fragment at position 1 is essential for activity. The ...

Urokinase (uPA) is a 411 residues serine protease originally identified for its ability to activate plasminogen and generate plasmin, a broad-spectrum matrix- and fibrin-degrading enzyme. Later, this protease has been shown to possess also a clear-cut ability to stimulate cell migration and survival in a catalytic-independent manner. This activity turned ...

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the interconversion of inactive cortisone to active cortisol in a NADPH dependent manner. Excess cortisol or 11β-HSD1 leads to insulin resistance and metabolic syndrome. Inhibition of 11β-HSD1 activity has been pursued vigorously by the pharmaceutical industry as a potential therapeutic strategy for the treatment ...

ABSTRACT: Toward development of a safe and effective treatment for Alzheimer's disease, Elan Pharmaceuticals reported a novel γ-secretase inhibitor that specifically targets the cleavage of amyloid-β precursor protein, opening the way to design of substrate-specific γ-secretase inhibitors that would reduce the amyloid burden without significant adverse events.

Class C β-lactamases mediate antibiotic resistance in bacteria by efficiently hydrolyzing a broad range of β-lactam antibiotics. With their clinical significance and the lack of commercially available effective inhibitors, development of class C β-lactamase inhibitors has become one of the recent hot issues in the pharmaceutical industry. In this paper, ...

Substituted urea compounds are well-known as potent inhibitors of juvenile hormone epoxide hydrolase (JHEH) of the tobacco hornworm Manduca sexta. Docking simulations of 47 derivatives inside JHEH were performed to gain insight into the structural characteristics of these complexes. The obtained orientations show a strong similitude with the observed in ...

Lemongrass volatile oil (LVO) is an important ingredient in cosmetics, presenting antimicrobial properties, in particular antifungal activity, and it is a promising raw material for the development of pharmaceutical products. However, its volatility and susceptibility to degradation are the major drawbacks for the use of Cymbopogon citratus oil in pharmaceutical ...

Integrin conformational changes mediate integrin activation and signaling triggered by intracellular molecules or extracellular ligands. Even though it is known that αβ transmembrane domain separation is required for integrin signaling, it is still not clear how this signal is transmitted from the transmembrane domain through two long extracellular legs to ...

The small GTPase Rap1 and the cytoskeletal protein talin regulate binding of C3bi-opsonised red blood cells (RBC) to integrin α(M)β(2) in phagocytic cells, although the mechanism has not been investigated. Using COS-7 cells transfected with α(M)β(2), we show that Rap1 acts on the β(2) and not the α(M) chain, and ...

Although the precise intracellular roles of S100 proteins are not fully understood, these proteins are thought to be involved in Ca(2+)-dependent diverse signal transduction pathways. In this report, we identified importin α as a novel target of S100A6. Importin α contains armadillo repeats, essential for binding to nuclear localization signals. ...

Integrins are postulated to undergo structural rearrangement from a low affinity bent conformer to a high affinity extended conformer upon activation. However, some reports have shown that a bent conformer is capable of binding a ligand, whereas another report has shown that integrin extension does not absolutely lead to activation. ...

Negative stain electron microscopy (EM) and adhesion assays show that alpha(X)beta(2) integrin activation requires headpiece opening as well as extension. An extension-inducing Fab to the beta(2) leg, in combination with representative activating and inhibitory Fabs, were examined for effect on the equilibrium between the open and closed headpiece conformations. The ...

The platelet integrin α(IIb)β(3) is essential for hemostasis and thrombosis through its binding of adhesive plasma proteins. We have determined crystal structures of the α(IIb)β(3) headpiece in the absence of ligand and after soaking in RUC-1, a novel small molecule antagonist. In the absence of ligand, the α(IIb)β(3) headpiece is ...

We show that the length of a loop in the β-knee, between the first and second cysteines (C1-C2) in integrin EGF-like (I-EGF) domain 2, modulates integrin activation. Three independent sets of mutants, including swaps among different integrin β-subunits, show that C1-C2 loop lengths of 12 and longer favor the low ...

Transmembrane (TM) helices engage in homomeric and heteromeric interactions that play essential roles in the folding and assembly of TM proteins. However, features that explain their propensity to interact homomerically or heteromerically and determine the strength of these interactions are poorly understood. Integrins provide an ideal model system for addressing ...

The recently published novel integrin alpha(IIb)beta(3) ectodomain crystallographic structure and NMR structures of its transmembrane/cytoplasmic segments were employed to refine previously developed molecular models. Alternative complete alpha(IIb)beta(3) models were built and evaluated, and their shape was compared with EM maps and their computed hydrodynamic/conformational properties were compared with the available ...

Integrin alpha(4)beta(1) is an attractive but poorly understood target for selective diagnosis and treatment of T-cell and B-cell lymphomas. This report focuses on the rapid microwave preparation, structure-activity relationships, and biological evaluation of medicinally pertinent benzimidazole heterocycles as integrin alpha(4)beta(1) antagonists. We documented tumor uptake of derivatives labeled with (125)I ...

Cell surface receptors of the integrin family are pivotal to cell adhesion and migration. The activation state of heterodimeric alphabeta integrins is correlated to the association state of the single-pass alpha and beta transmembrane domains. The association of integrin alphaIIbbeta3 transmembrane domains, resulting in an inactive receptor, is characterized by ...

Integrin signaling is comprised of well-characterized pathways generally involved in cell survival. alpha(9)beta(1) integrin has recently become a target of study and has been shown to present pro-survival effects on neutrophils. However, there are no detailed studies on how alpha(9)beta(1) integrin-coupled signaling pathways interact and how they converge to finally ...

The main interface of the 2 subunits of platelet integrin alphaIIbbeta3 comprises the beta-propeller domain of alphaIIb and the betaA domain of beta3. In the center of the beta-propeller, several aromatic residues interact by cation-pi and hydrophobic bonds with Arg261 of betaA. In this study, we substituted alphaIIb-Trp110 or beta3-Arg261 ...

Collagen is a popular biomaterial. To deal with its lack of thermal stability and its weak resistance to proteolytic degradation, collagen-based materials are stabilized via different cross-linking procedures. Regarding the potential toxicity of residual cross-linking agents, enzyme-mediated cross-linking would provide an alternative and nontoxic method for collagen stabilization. The results ...

Deseasin MCP-01 is a bacterial collagenolytic serine protease. Its catalytic domain alone can degrade collagen, and its C-terminal PKD domain is a collagen-binding domain (CBD) that can improve the collagenolytic efficiency of the catalytic domain by an unknown mechanism. Here, scanning electron microscopy (SEM), atomic force microscopy (AFM), zeta potential, ...

Integrins are cell adhesion receptors that transmit bidirectional signals across plasma membrane and are crucial for many biological functions. Recent structural studies of integrin transmembrane (TM) and cytoplasmic domains have shed light on their conformational changes during integrin activation. A structure of the resting state was solved based on Rosetta ...

Talin is a 270-kDa protein that activates integrins and couples them to cytoskeletal actin. Talin contains an N-terminal FERM domain comprised of F1, F2 and F3 domains, but it is atypical in that F1 contains a large insert and is preceded by an extra domain F0. Although F3 contains the ...

Integrins, heterodimers of alpha and beta subunits, are a family of cell surface molecules mediating cell-cell and cell-extracellular matrix interaction. The largest subgroup is formed by the beta(1) subunit containing integrins which consist of 12 members with different ligand-binding properties. We previously reported that overexpressed integrin beta(1) subunit in the ...

Integrins play critical roles in the process of angiogenesis and are attractive targets for anticancer therapies. It is desirable to develop new types of small-molecule inhibitors of integrin. Herein, the binding features of several inhibitors to integrin alpha(v)beta(3) have been studied by surface plasmon resonance (SPR) biosensor technology and molecular ...

The outstanding physio-pathological role played by integrin receptors in living subjects motivates the enormous interest shown by scientists worldwide for this topic. More than twenty years of research has spanned across the structural and functional elucidation of these proteins and over their antagonism-based biomedical applications. The proof-of concept stage, aimed ...

Enzymatic processing of extracellular matrix (ECM) macromolecules by matrix metalloproteases (MMPs) is crucial in mediating physiological and pathological cell processes. However, the molecular mechanisms leading to effective physiological enzyme-ECM interactions remain elusive. Only scant information is available on the mode by which matrix proteases degrade ECM substrates. An example is ...

We report the structure of an integrin with an alphaI domain, alpha(X)beta(2), the complement receptor type 4. It was earlier expected that a fixed orientation between the alphaI domain and the beta-propeller domain in which it is inserted would be required for allosteric signal transmission. However, the alphaI domain is ...

Interactions between transmembrane (TM) helices play an important role in the regulation of diverse biological functions. For example, the TM helices of integrins are believed to interact heteromerically in the resting state; disruption of this interaction results in integrin activation and cellular adhesion. However, it has been difficult to demonstrate ...

Phosphoinositide (PI) 3-kinase (PI3K) signaling processes play an important role in regulating the adhesive function of integrin alpha(IIb)beta(3), necessary for platelet spreading and sustained platelet aggregation. PI3K inhibitors are effective at reducing platelet aggregation and thrombus formation in vivo and as a consequence are currently being evaluated as novel antithrombotic ...

Collagens of either soft connective or mineralized tissues are subject to continuous remodeling and turnover. Undesired cleavage can be the result of an imbalance between proteases and their inhibitors. Owing to their superhelical structure, collagens are resistant to many proteases and matrix metalloproteinases (MMPs) are required to initiate further degradation ...

The globular head domain of talin, a large multi-domain cytoplasmic protein, is required for inside-out activation of the integrins, a family of heterodimeric transmembrane cell adhesion molecules. Talin head contains a FERM domain that is composed of F1, F2, and F3 subdomains. A F0 subdomain is located N-terminus to F1. ...

The beta3 integrin family members alphaIIbeta3 and alphaVbeta3 signal bidirectionally through long-range allosteric changes, including a transition from a bent unliganded-closed low-affinity state to an extended liganded-open high-affinity state. To obtain an atomic-level description of this transition in an explicit solvent, we carried out targeted molecular dynamics simulations of the ...

Hemidesmosomes (HD) are adhesive protein complexes that mediate stable attachment of basal epithelial cells to the underlying basement membrane. The organization of HDs relies on a complex network of protein-protein interactions, in which integrin alpha6beta4 and plectin play an essential role. Here we summarize the current knowledge of the structure ...

Heterodimeric integrin adhesion receptors regulate diverse biological processes including angiogenesis, thrombosis and wound healing. The transmembrane-cytoplasmic domains (TMCDs) of integrins play a critical role in controlling activation of these receptors via an inside-out signaling mechanism, but the precise structural basis remains elusive. Here, we present the solution structure of integrin ...

Plasminogen activators are implicated in the pathogenesis of several diseases such as inflammatory diseases and cancer. Beside their serine-protease activity, these agents trigger signaling pathways involved in cell migration, adhesion and proliferation. We previously reported a role for the sphingolipid pathway in the mitogenic effect of plasminogen activators, but the ...

Rhodostomin (Rho) is a snake venom protein containing an RGD motif that specifically inhibits the integrin-binding function. Rho produced in Pichia pastoris inhibits platelet aggregation with a K(I) of 78 nM as potent as native Rho. In contrast, its D51E mutant inhibits platelet aggregation with a K(I) of 49 muM. ...

We determined the crystal structure of 1TM-alphaVbeta3, which represents the complete unconstrained ectodomain plus short C-terminal transmembrane stretches of the alphaV and beta3 subunits. 1TM-alphaVbeta3 is more compact and less active in solution when compared with DeltaTM-alphaVbeta3, which lacks the short C-terminal stretches. The structure reveals a bent conformation and ...

The alpha(v)beta(3)- and alpha(5)beta(1)-integrins play a key role in angiogenesis, the formation of new vessels in tissues that lack them. By serving as receptors for a variety of extracellular matrix proteins containing an arginine-glycine-aspartic acid (RGD) sequence, these integrins mediate migration of endothelial cells into the basement membrane and regulate ...

The integrin alpha6beta4 is a receptor for laminins and provides stable adhesion of epithelial cells to the basement membranes. In addition, alpha6beta4 is important for keratinocyte migration during wound healing and favours the invasion of carcinomas into surrounding tissue. The cytoplasmic domain of the beta4 subunit is responsible for most ...

Laminins are large heterotrimeric glycoproteins with many essential functions in basement membrane assembly and function. Cell adhesion to laminins is mediated by a tandem of five laminin G-like (LG) domains at the C terminus of the alpha chain. Integrin binding requires an intact LG1-3 region, as well as contributions from ...

We investigated the molecular bases of spondyloepiphyseal dysplasia (SED) associated with the R992C (p.R1192C) substitution in collagen II. At the protein level, we analyzed the structure and integrity of mutant molecules, and at the cellular level, we specifically studied the effects of the presence of the R992C collagen II on ...